The present inventions relate generally to container return systems and, more particularly, to improved container pick and return systems that permit the efficient delivery of containers and their contents to an access aisle for easy and adjustable unloading and the automatic return of empty containers to a loading aisle. The present inventions are particularly advantageous when used in assembly line applications, such as the automotive industry. However, they are equally pertinent to a wide variety of other applications.
In assembly line applications, for example, an important consideration is the constant supply of parts, typically of a wide variety of sizes, shapes and weights, to the assembly line worker. Ease of access to these parts, the removal of empty parts containers, and the re-supply of parts are also important considerations to the overall efficiency of the process. Any delay in the flow of parts, any difficulty in access to parts or any difficulty in removing empty containers can lead to inefficiencies in the entire assembly line process.
Systems capable of accommodating these considerations are shown and described in U.S. Pat. No. 6,186,725 B1 to Konstant, entitled xe2x80x9cContainer Pick and Return System,xe2x80x9d U.S. Pat. No. 5,567,103 to Konstant and U.S. Pat. No. 5,642,976 to Konstant, both entitled xe2x80x9cUnloading Devicexe2x80x9d (the xe2x80x9cKonstant patentsxe2x80x9d) (all of which are incorporated herein by reference).
The latter two Konstant patents teach, among other things, container unloading systems that selectively and automatically cycle carts carrying unit loads, such as containers or parts bins, to the front (or access aisle) of the system where the load is held at an angle for unloading. The system then cycles (returns) the carts and unloaded unit containers to the rear of the system (loading aisle) for re-loading and re-use. In other such systems, pallets or bins ride on pairs of parallel flow rails and carry the unit loads to the access aisle for use. The empty unit loads may then be selectively and automatically returned to the rear of the system for reloading.
The first referenced Konstant patent teaches, among other things, a container pick and return system having a transfer conveyor assembly that, upon receipt of a loaded container, automatically and smoothly positions the container at an angle increased from the angle of the input conveyor assembly to enhance the accessibility of the contents of the container. When the container is empty, the transfer conveyor assembly is selectively triggered and the empty container is automatically transferred to the exit conveyor for unloading.
Other available systems require the use of air cylinders, solenoids and motors to cycle unit loads. One such system is the Roll""n Lift system by Creative Storage Systems, Inc. of Kennesaw, Ga. Such devices utilize relatively complex electronics and pneumatics to present a pallet and return unloaded pallets and the like. Such systems also suffer from, among other things, their expense, complexity and high maintenance.
In some applications, it is desirable to eliminate the necessity of wheeled carts used to carry the unit loads. In this manner, there is greater flexibility of unit load size and systems costs, and associated maintenance and shipping costs, may be reduced. For similar reasons, it is also desirable to eliminate the need for and complexity of electronically controlled air cylinders, pneumatics and motors.
Moreover, it is also desirable to have an efficient and smooth system that can be effective with heavy loads and provide the gentle presentation of such loads to the transfer conveyor. Further, it is learned that many in the industry believe it is desirable for the operator or line worker to be able to selectively adjust the angle of presentation of a parts container or other load.
The present inventions preserve the advantages of container unloading and return systems and also provide new features and advantages. For example, the present inventions provide container unloading systems that can deliver unit loads, parts container bins and the like to an access aisle and smoothly present the loads at an operator selected angle of presentation for ease of access. The empty containers may then be automatically and selectively returned for refilling and another loaded container may automatically take its place. Such systems can accommodate a wide variety of load sizes, shapes and weights, including relatively heavy loads, all without the use of carts or complex electronically controlled pneumatics and the like.
In a preferred embodiment of the present inventions, a container pick and return system is provided having a two-tiered flow rail conveyor system that includes an inclined upper set of feed flow rails forming an input conveyor assembly and a lower set of inclined return flow rails forming an exit conveyor assembly upon which a unit load may roll. At the front end of the system is a transfer conveyor assembly that receives a loaded container. The line worker may then operate a locking spring control pedal that permits the container to be positioned at any desired angle greater than the angle of the input conveyor. This permits enhanced accessibility of the contents of the container regardless of the height or arm length of the line worker or the size and shape of the container and its contents. When the container is emptied by the line worker, the transfer conveyor assembly is triggered and the empty container is automatically lowered and transferred to the exit conveyor where it rolls down the exit conveyor to the rear of the system for reloading. Upon transfer of the empty container, the transfer conveyor assembly automatically returns to an upper position for receipt of another loaded container and subsequent presentation of the contents of the container. A transfer trigger mechanism is provided to enable the selective transfer and return of unloaded containers through the activation of the transfer function. In addition, a container stop may be provided on the input conveyor so that a number of containers may wait in line behind one another in multiple depths on the input conveyor to be selectively advanced to the transfer conveyor assembly for use.
Accordingly, an object of the present invention is to provide a unit load unloading conveyor system that automatically returns empty containers, unit loads, pallets and the like to the rear of the system for reloading.
Another object of the present invention is to provide a transfer and return system that minimizes interference with the efficiency of the assembly line process by providing a steady stream of parts to the assembly line worker.
A further object of the present invention is to provide a smooth container return system that is effective for heavy loads and does not require the use of wheeled carts.
An additional object of the present invention is to provide a container unloading system that smoothly presents the contents of a container at an angle, that selected by the operator, for ease of use and unloading and then smoothly, selectively and automatically transfers the unloaded container to the rear of the system.
Still another object of the present invention is to use locking gas springs and dampers in a container unloading system that smoothly and gently effectuates container presentation and transfer, which is also applicable for use with a wide variety of load weights, including heavy loads.
Still a further object of the present invention is to provide a container unloading system that automatically, selectively and smoothly transfers unloaded containers from an unloading end to a loading end where they may be stored or re-used.
Yet an additional object of the present invention is to eliminate the need for solenoids, motors and the like for a container unloading and return system, although such items may be used on or in conjunction with systems of the present invention.
Yet another object of the present invention is to provide a container unloading system that can accommodate multiple depths of containers and a wide variety of container contents.
Yet a further object of the present invention is to provide an unloading system that can be used in combination with other such systems and that can be used in conjunction with other transfer of storage and/or delivery systems.
The terms used in the claims of this patent as filed are intended to have their broadest meaning consistent with the requirements of law. Where alternative meanings are possible, the broadest meaning is intended. All words used in the claims are intended to be used in the normal, customary usage of grammar and the English language.